Call-metering system



F. M. SLOUGH.

CALL METERING SYSTEM.

APPLICATION FILED sEPL2s. 191a.

Patented Aug. 16, 1921.

INVENTOR UNITED STATES PATENT OFFICE.

FRANK M. SLOUGH, OF ROCHESTER, NEW YORK, ASSIGNOR TO THE STROMBERG-ROCHESTER, NEW

YORK, A CORPORATION OF NEW YORK.

CALL-METERING SYSTEM.

Specification of Letters Patent.

Patented Aug. 16, 1921.

Application filed September 26, 1918. Serial No. 255,736.

To all whom it may concern."

Be it known that I, FRANK M. SLOUGH, a citizen of the United Statesresiding at Rochester, in the county of Monroe and State of New York,have invented certain new and useful Improvements in Call-MeteringSystems, of which the following is a full, clear, concise, and exactdescription.

My invention relates to a telephone service meter, and its object is toprovide an improved organization of circuits and apparatus whereby givenconnection cannot be registered more than once.

A further object is to provide means whereby after a connection has oncebeen registered, a subsequent attempt to register the same connectionwill be unavailing, certain safe guards having been provided to preventre-registration until the entire connection has been taken down and anew connection established.

A further object is to provide a signal operated previous to theresponse of a called for subscriber when a connection has beenestablished between a calling line and the line of the calledsubscriber, and to extinguish the said signal when the called subscriberresponds.

A further object of my invention is to provide a key individual to aconnecting circuit, whereby an operator may control the registrationfunction.

A further object of my invention is to provide means wherein theaforesaid objects are attained in a circuit wherein the regis ter isconnected to a limb of the calling line, and in such a system whereinthe register circuit associated with the line must be of relatively highresistance.

Other objects of my invention and the inention itself will be moreclearly underl the description thereof progresses.

AQLQlIlHg to the figure accompanying this s ecification, at Al showcalling subapparatus connected to the limbs of a line L1, by which thecalling substation is connected to terminal line apparatus at thecentral office, the said terminal line apparatus comprising a line relayLR. controlling a line lamp L.L., a cut-off relay CUR, a register REG.,a terminal jack for the line J. A called line is shown at L2 terminatingin substation apparatus B cennecting the said substation apparatus tothe exchange. The line apparatus for both of the lines L1 and L2 may be,and is illustrated as being of the same nature. A line interconnectinglink circuit is shown at 0, comprising talking strands for each end ofthe link circuit terminating at one end in a plug Pl for the answeringend and a plug P2 at the calling end of the connecting circuit, thetalking strands for both ends being inductively linked by means of thewindings of a repeating coil. An operators circuit is shown at 0 adaptedto be connected by means of a key K to the talking conductors of theconnecting circuit. A. supervisory signal lamp SA. is provided for theanswering end of the connecting circuit, a corresponding signal lamp SE.being provided for the calling end of the connecting circuit. Ninerelays are provided for the cord connecting circuit illustrated, themagnets for these relays being indicated in the drawing at #1, #2, #3,#4, #5, #6, #7 and #8.

Contact controlling aimatures for the above numbered relays are shown atdifferent points of the figure, being variously placed as a matter ofconvenience in tracing the described circuits, the armatures beingidentified with their controlling electromagnets by being referencedwith the same numeral as used for indicating the particular controllingmagnet for a particular armature. All of the contacts for the saidarmatures and also the apparatus of the entire system illustrated, isshown in normal unoperated condition.

To make the above perfectly plain, for example, a magnet referenced #4is shown connected to the lower terminal of the winding 3 of theconnecting circuit repeating coil. This magnet carries two armatiu'es,the one being shown at the bottom and in the middle of the figure, theother being shown above and to the left of: the first mentionedarmature. It is to be understood. that each of these armatures closetheir associated contacts simultaneously when the magnet #4 issutliciently energized by the flow of current through its winding.

The registers for each of the lines shown at REG. for line and at REG. 2tor the called line are preferably constructed having two windings, oneof which is permanently connected in circuit with the terminal of thespring jack J for the calling line and J2 for the called line register,the other being so connected only when the register has fully attractedits armature. The registers may operate their counting members which maybe of any well known construction and which are not specificallyillustrated but understood, upon the forward stroke of the registerarmature, or upon the back stroke thereof. The registers operatingeither way are well known in the art to which this invention appertains.

In the embodiment of my invention illustrated in the drawing, the lineregisters are incorporated in a well known form of line circuitinvolving a cut-off relay shown at (1013. having two differentialwindings one of which, the upper, is permanently con nected to a limb ofthe line, the other of which is connected through normal. contacts ofthe relay (10R. to the other limb of the line, the line relay for theline being serially connected in circuit with the second winding. Inthis line circuitot the art, when current flows from the central officethrough one of the said windings over the line including the subscriberssubstation apparatus, returning through the other winding of the cut-offrelay Call-t, the two windings being traversed by the same current andbeing of equal effect upon the armature and being differentiallyconnected, no operation of the armature of the cutofl relay will takeplace, but the serially connected winding of the line relay LR. willcause it to be operated to light the line lamp. The responding operatorinserting an answering plug P1 into the calling line jack J, will upsetthe balanced. condition existing between the two windingsbeforementioned by connecting a source of current to the first mentionedpermanently connected winding to increase the effect of this permanentlyconnected winding, at the same time producing a shunt upon the secondwinding, and the relay (3.0.11. will operate to disconnect the secondwinding and the serially connected line relay from the second lineconductor.

In the embodiment of my invention illustrated, I connect the lower andoperating winding of the register REG. in serial circuit with thepermanently connected upper winding of the relay (10.1%. The register isoperated by projecting over the corresponding talking strand 6 of theassociated connecting circuit, a current from a source of higherpotential than that normally connected to the said strand to traversethe windings of the relay C.O.R-. and of the register REG. which arepermanently connected to a talking strand of the line circuit. Theregister will then attract its armature, closing contacts 7 to connectthe upper winding of the register to the talking strand 8 of the linewhich at the time is connected to the talking strand 6 of the connectingcircuit, the closing of the, register contact thus placing the saidupper register winding in multiple with the lower winding and seriallyconnected upper winding of the relay C.O.R., the result of thisestablished multiple circuit being that the resistance from the talkingconductor 8 of the line to ground will be made very much lower than thatpreviously obtained, and the flow of current from the high potentialsource will be greatly augmented.

Art the time the marginal relay #8 is operated as before described, thesaid relay #7 is retired under the control of the said relay #8, and therelay #8 will be operatively locked so as to prevent the reenergizationof the said relay #7 while either the answering plug P1 or the callingplug remains in the connected line jacks, thus preventing a reconnectionot the said source of high potential current to the line registercircuit. Below the downwardly extending circuit conductors 10, 11 and 12to which they lead, is shown a ringing trip relay #6, varlous relaycontacts, a ringing key #13, a ringing generator #14, and a ringingcircuit interrupter #15, together with associated apparatus andconductors, the above mentioned apparatus and conductors operating inconnection with ringing relay #5 to perform the function ofautomatically and periodically ringing the called line subscriber at B,and for removing the ringing current upon the response of the saidsubscriber.

A brief description of the operation of the circuits illustrated willnow be had for a better understanding of the invention:

The subscriber at A calling, establishing the talking bridge of the lineby removing his receiver from the hook will operate the line relay LR,causing the display of the line lamp LL. in the usual manner. Theoperator responding, will make connection with the calling line byinserting the plug P1 into the jack J, and thereby connect the talkingstrands 8 and 160i the calling line to the talking strands 6 and 17 ofthe connecting circuit. The differential relay GU11. hithertoLin-responsive to equal current flowing through both its windings, isnow operated by a reinforcing flow of current through a circuit tracedas tollows; the said current flowing through the upper winding of thesaid relay: From the negative pole of the source o1 current, relaywinding #1, normal contacts 18 associated with an armature #7A of relay#7, the winding 2 of the repeating coil, talking strand 6 of theconnecting circuit, talking strand 8 of the line circuit, upper windingof relay C.O.R., lower operating winding of register REG. to ground.Current from the said source will flow through the said windings inaddition to the line current, through the calling substation apparatusand the relay C. O. R. will be operated. lVhcn operated, it will breakthe circuitof the line relay LR. at contacts 19, and extend the circuitof the talking conductor 16 of the line to the test contact 20 of thejack thereof, for busy tone purposes. The contacts 19 being open, therelay LR. will be retired, retiring the line lamp LL. Current from theabove mentioned source of current will not flow through the lowerwinding of the register in sufficient strength to operate the saidregister, the said register having a marginal adjustment and beingirresponsive to low current strengths.

Current to the calling substation transmitter T will now be suppliedover a. circuit traced as follows: from the ground pole of battery, thelower winding of the register, the upper winding of the relay C. O. R,line talking strand 8, substation transmitter T and receiver R,switchhook and contact 21, line talking strand 16, connecting circuittalking strand 17, winding at of the connect ing circuit repeating coil,normal contacts 22 of the relay #7, the winding of relay #2 to thenegative pole of the source of current. Current from the said sourcewill flow over the said circuit energizing the re lay #2. Relay #1 ofthe connecting circuit is also at the time energized over a part of thesame circuit, the circuit for relay #1 being traced as follows: from theground pole of battery, a winding of the register REG, the upper windingof the relay C.O.R., line talking strand 8, connectin circuit talkingstrand 6, the winding 2 or the connecting circuit repeating coil, normalcontacts 18 of the relay #7, the winch ing of the relay #1 to thenegative pole of the source of current. Relays #1 and #9 are thereforeat the time energized in addition to the relay C.C.R. Relay #2 attractsits armatures, causing the operation of relay #2A which relay is for thepurpose of operating relay contacts whenever relay is operated. thuslightening the relay contact load upon the armature of relay #a. Alsothe introduction of the winding of relay #2A in the circuit providesanother path to ground from the tip talking strand to increase thesupply of transmitter battery current to the calling substation.

The supervisory signal lamp SA. :for the answering end of the cordcircuit will not at this time be operated, because of the presence ofthe subscribers substation instrument upon the line, thus opening thecontacts 23 in its energizing circuit. The operator attending the callin the usual way will operate her listening key K, and will conversewith the calling subscriber learning the number of the called linestation, connection to which will be made by inserting the calling pluginto the jack J2, the listening ke being restored to normal. A circuitwill now complete to operate the of? relay C0. of the called line, thecirincluding the winding of the relay 1. and the winding of relay #4,said circuit also inchiding central ollice source of current, thewinding #3 of the re ieatiug coil, tip talking st rand ot the connectingcircuit, tip talking strand of the called line, and the lower windin oithe called line register REG. 2. Relays l and CC. will be operated. theregister however having a marginal adjustment will not be operated.Ringing of the called subscribe:"s station will take place upon theoperators depressal of one of the ringing keys provided, such theringing key 1?: of the connecting circuit. Upon such a doprcssal commonend key contacts will he momentarily closed and 6 opened. The cl ire ofthese contacts will establish a circuit for the winding. oi? ringingrelay the said circuit including the central oilicc source ot current;the said circuit may be traced as follows: from the ground le ofbattery, now closed contacts of relay #4:. normally closed contacts 26of relay #3, now closed contacts 27 of relay #2A, now closed contacts 28or? relay #1 77""? the end key spring contacts 2 1, momentarily closed.the winding of the relay #5, the re tancc coil R13. to the n u'cc clcurrent. Current "mm the said sour 1c will operate the relay and whenthe said relay will opcratrrel lock \e pole of the 1 c urc of contacts29 oi the said wlu are bridged across the momenclosed the contacts 30 atthe said key to extend the circi :hc rn crater ll. c! the circuit from l0 ground Wllaltcn natcly through the u' i'upj ol the ringing l now closc ii 1 oil the relay #5 :22 1 over the r line through rcllcd linefillllfll'l lll'h signal bell till, 'ctuning over the other side ol' theline h n w cl sed contacts 3 3 rd relay h win-inductive r lancc 3G tothe \c pole ol the 05" current. ever the ca led l) rc spends by takinghis recei' 0 heel; and thus completing a. conduct .c bridge of the linewires, the relay #6 will be operated. the said relay being irresponsireto the 'ignalin g current from the {IGHQ='1Et2l' 14, but

' e to the flow of direct cu"- he central oi'iice source of: current.

.y #6 is thus operated. it-w l cl "s 37 to sho circuit the winding ofthe lay which will now det nergire breaktit from REG. is nowconditioned.

ing its locking contacts 29 and restoring the normal contacts 38 in thesleeve talking strand of thecord circuit. At this point, theregistration of the call on the calling subscribers line meter REG. willordinarily take place provided that the registration key RK. has beenpreviously set.

This registration key may be a locking key and when so constructed maybe entirely set, and when so set may be left in this con dition so thatthe registering will be accomplished automatically without any furtherattention from the operator or, the key may be made non-locking and ineither case may be operated manually by the operator after the twosubscribers are in conversational circuit according to the method ofoperation desired, either method being supplied with the same safeguards and provisions as the other, the circuit operations being alikein both cases.

Assuming that the key RK. has been previously set or is now operated,relay #7 will be operated whenever the circuits are in condition forregistration, that is, whenever on a new connection put up by means ofthe connecting circuit C, both subscribers are operatively connected inconversational circuit, a conditions being that no registration shouldhave already been made during the said conversationalperiod initiated bythe response of the called subscriber. At the time of such aresponse anduntil the registration has taken place, a circuit is completed for theoperators register lamp BL, traced as follows: from the negative pole ofthe source of current through the said register lamp RL, through nowclosed contacts 39 of the operated register key R.K., normal contacts 40of the marginal register trip relay #8, through multiply connectedcontacts l1 and 42 of relays #213. and to the ground pole of the sourceof current. The lighting of the signal lamp will indicate that anoperation by the calling, register At the same time relay #7 operatedover a circuit traced as follows: from the ground pole of battery,multiply connected contacts 4C1 and -12 of relays #QA and #4, normalcontacts 40 0f relay #8, now closed contacts 39, now closed contacts 43of relay #3, now closed contacts 44: of relay :ll-QA, winding of relay#7, resistance coil 15, to the negative pole of the source of current.Current from the said source will operate the said relay #:7 to projecthigh potential registering current over the calling line registercircuit, as will be later described.

The relay #7 is preferably constructed in acordance with the relayconstruction set forth in my application, Serial No. 185,636, December7, 1916, although this is not essen tial in order to carry out the mainpurposes of my invention but, some such construction is required inorder to carry out some of the other objects thereof. T he saidapplication illustrates a relay having a plurality of contact operatingarmatures, one of the said armatures having a magnetic shielding eifecton the other, this construction causing the relay when energized tooperate the shielding armature before operating the shielded armature.Such a structure therefore enables one to have in a single relaystructure a fast operating and slow operating contact controllingarmature. For the relay #7, the armature $571k is the slow operatingarmat-ure, the others being relatively fast operating. In this way 1 amenabled to operate the relay #7, to cause the operation of the first orfast armature which will operate contact as to condition the circuitsfor the application of high potential current and thereafter apply bymeans of the slow operating armature thesaid high potential registercurrent. The contact at of the relay #7, fast operating, short circuitsthe winding 2 of the repeating coil, this being done to lessen the clickin the connected subscribers receivers, incidental. to the quickfluctuations of current in the talking strands 6 and 8 of the system,absorbing in a. large measure the energy due to such fluctuations whichwould audibly operate the diaphragm of the receiver of the connectedsubscriberf The relay being operated, contacts 17 thereof are closed toproduce a locking circuit for the relay #7 independent of the contacts4:3 and 44.: of relays #3 and :tt-ZA respectively, and independent ofthe contacts 39 of the register key llcii, this locking circuit bridgingthe said contacts, being for the purpose of preventing the breaking downof the registering condition prior to the actual registration due topossible quick openings of any of the said contacts.

The operation of the key Elli. breaks contacts 48 which normally bridgecontacts 18 of relay #7. The fast armature of relay #7 having operatedto close contacts 46 and 47 and to open contacts 22, the slow armaturewill now be operated to break contacts 18 and close contacts 49. Thebreaking of contacts 18 disconnects the relays #1 and :ttE EA normallybridged to the tip strand 6 of the connecting circuit from the said tipstrand, the closing of the contacts 19 extends the high potentialcurrent register source H.P. to the said tip strand, and the completecircuit being traced as follows: from the gro und through the said highpotential source of current, the positive pole of which is connected toground, the protecting resistance unit U, now closed contacts 50 of theregister key lit-. 51, the shunted operating winding OW. of relay #8with its non-inductive shunt Nl, now closed contacts 19 of the relay #7,now-closed contacts 16 of relay #7, the talking strand 6 of theconnecting circuit talking strand 8 of the calling line circuit, theoperating winding of the relay and the operating winding of theregisteto ground.

\Vhereas I may operate all the other circuits the system outside of theringing circuit from a single source of direct current compri ing astorage battery of nerhaps 40 volts, 1 find that in order to properly operate the registering system of my invention a higher voltage source ofcurrent is required to operate the register REG. when the said registeris given such an adjustment that it will be irrcsponsive to othersources of current before mentioned, including the 40 volt source andthe ringing generator source. I therefore make the voltage of theregistering generator ill. considerably higher, a voltage of 90 voltshaving been found to be quite satisfactory in practical demonstration ofa system embodying my invention.

The flow of current over the circuit HP. just described including awinding of the register is therefore of considerable strength and willoperate the said register to cause it to fully attract its armature.lVhen the register has fully attracted its armature.contact T ope 'atedthereby ill be closed shunting that portion of the registration circuitjust described, which includes a winding each of the register and thecut-off relay (10.18.. reducing the resistance of this portion of thecircuit very materially and greatly augmenting the flow of registrationcurrent from the source HP. and which flows through the shunted windingOdfi of the marginal registration trip relay #8. it the time theregistration current is applied to the tip strand 8 of the line asbefore described, some of this current momentarily flows over the lineand through the calling substation instrument, back over the sleeve side16 of the line and the sleeve strand 1? of the connectim circuit,repeating coil, winding 4 thereof and, the contacts 22 of relav #l"being open. through contacts 51 of relay the winding of the said relayto the negative pole of the low voltage source of current. Due to thehigher voltage of the high potential source of current over the linecircuit and through the winding of relay the flow of current is reversedin direction, this reversal momentarily (lo-magnetizing relav andcausing relay #2 to retract its zirniatures breaking the contact 51 inits circuit. This circuit being broken at the contacts 51 cannot bere-established, so that the winding of relay #2 is for the presentremoved from the line circuit and all of the registration current fromthe high potential source after the opening of the said contacts passesthrough the register windings alone, and none of it passing over theline. The augmented flow due to the closure of contact 7 of the registeras before described, 0perates the marginal relay #8, which w1ll attractits armature breaking contacts 40 and closing contacts 52. The breakingof contacts 40 removes the short circuit normally established about thewinding H.\V. of relay #8, which winding is the holding winding, andrelay #8 is maintained operative after the breaking of the contacts 40by current through this winding H.\V., a circuit for the flow of currenttherethrough being traced as follows: from the ground pole of battery,through the contacts 42 of relay #4, the said winding H.W., key contacts39 of the key R.K., the signal lamp BL. to the negative pole of thesource of current. The armature 9 further advancing to close thecontacts 52, the signal lamp is shunted by the resistance coil 45, whichis likewise connected to the negative pole of the source of current.

At the time the contacts 52 are closed, relay #7 is short circuited bythe said contacts, the short circuit being traced as follows: from aterminal of the winding of relay #7, now closed contacts 47 thereof, nowclosed contacts 52 of relay #8 to the other terminal of relay #7. Relay#7 now deenergizes to retract its armature and break the contacts 47 inthe circuit of its winding, the said short circuit preventing itsreoperz tion under any conditions except a complete restoral of theconnection to normal. The non-inductive resistance coil NI. about thewinding OJV. of relay #8 is of much lower resistance than the windingORV. in order that the said winding with its noninductive shunt will beas nearly non-inductive as possible, and still permit the winding tooperate the relay #8 at the proper time. This in order that arcing atthe contacts 49 may be prevented upon the breaking of contacts 49 whenthe relay #7 retracts its armatures breaking the registration circuit. Ifind that by so proportioning the non-inductive resistance and thewinding 01V. that the arcing otherwise existing at these contacts is soreduced as to be non-objectionable. By the method of control justdescribed for the relays #7 and #8, the operation of the said relays ismade positive and the operation of either of these relays is prevented,which operation might otherwise under some conditions cause are-registration of the calling line meter which, of course, is veryundesirable in practice. The relay #7 retracting its armatures, thecontacts operated thereby will occupy their normal positions shown inthe drawing, the relays #1, #2 and .A are again operated, and registerREG. is again restored to its normal position, this armature beingcompletely retracted.

The register fully retracts its armature after a complete operationbecause of the breaking of contacts 49 of relay #7 interrupting the flowof registration current from the high potential source H.P. The twowindings of the register are proportioned in a novel manner whereby I amenabled to achieve a novel result.

When the winding .0. of the register is shunted by the winding SW.thereof, the current flowing through the winding WVO. will of course beconsiderably reduced. I so wind the two register windings that theenergizetion of the register when both windings are effective issubstantially the same as when only the winding W.O. is effective, thatis, current flowing through the winding S N. will energize the registerto a degree determined by its ampere turns, and the two windings are soproportioned. that this particular number of ampere turns under thevarious conditions of use is substantially equal to the reduction inampere turns on the energization of the winding ,0, due to the shuntingof said winding. Due to these provisions when the contacts #7 of theregister close, they will not immediately open again due to the shunt ofthe winding W0. causing a vibration of the register armature, causing adisagreeable buzzing noise to be heard on the telephone line, andperhaps causing the register to operate improperly. hen the relay #QAagain opcrates after the registration period, contacts 41 are againplaced in multiple with contacts 4:2, and the holding winding. HJV. ofthe relay #8 will be jointly controlled by the said contacts of theserelays so that until both relays are retired which can only happen whenboth plugs are withdrawn from the calling and called line jacks, can therelay #8 be restored to condition the registration relay #7 for a secondregistration.

Vhile I have above described a specific embodiment of my invention, Iam. aware that numerous and extensive departures might be made from theembodiment illustrated without departing from the spirit of theinvention.

What I claim as my invention is defined in the following claims:

1. In a telephone system, thecombination with a telephone line, of acentral office 0011- nection switch, a line meter having a circuitadapted to be completed by said connection switch, the said line meterhaving contacts adapted to be closed when the said line meter isenergized, an operating winding for the saidline meter, a second windingtherefor, and adapted to be placed in multiple with the said firstwinding when the said contacts are closed, a marginal relay and a sourceof registration current adapted to be connected to the said line meterwhen a connecting circuit is associated with the said telephone line, bythe operation of the said connection switch, an armature for the saidmarginal relay adapted to be operated when the said line meter contactsare closed, but not operated prior to the closure of the said contacts,means under the control of the said armature to cause the saidregistration source of current to be dissociated from said line meterwhen the said armature is operated, and a holding circuit for the saidmarginal relay including a normally short circuited winding thereof.

2. In a telephone system, the combination with a telephone line, of acentral oflice connection switch, a line mete-r having a circuit adaptedto be completed by said connection switch, the said line meter havingcontacts adapted to be closed when the said line meter is energized, anoperating winding for the said line meter, a second winding therefor,and adapted to be placed in multiple with the said first winding whenthe said contacts are closed, a marginal relay and a source ofregistration current adapted to be connected to the said line meter whena connecting circuit is associated with the said telephone line, by theoperation of the said connection switch, an armature for the saidmarginal relay adapted to be operated when the said line meter contactsare closed, but not operated prior to the closure of the said contacts,means under the control of the said armature to cause the saidregistration source of current to be dissociated from said line meterwhen the said armature is operated, and a holding circuit for the saidmarginal relay including a normally short circuited winding thereof, thesaid short circuit for the said winding including normal contacts of thesaid marginal relay.

3. In a telephone system, the combination with a telephone line, of acentral oifice connection switch, a line meter having a circuit adaptedto be completed by said connection switch, the said line meter havingcontacts adapted to be closed when the said line meter is energized, anoperating winding for the said line meter, a second winding therefor,and adapted to be placed in multiple with the said first winding whenthe said contacts are closed, a marginal relay and a source ofregistration current adapted to be connected to the said line meter whena connecting circuit is associated with the said telephone line, by theoperation of the said connection switch, an armature for the saidmarginal relay adapted. to be operated when the said line meter contactsare closed, but not operated prior to the closure of the said con tacts,and means under the control of the said armature to cause the saidregistration source of current to be dissociated from said line meterwhen the said armature is operated, said meansincluding normally opencontacts of the said marginal relay, the windings of the said registerbeing so proportioned that the magnetic energization thereof is constantregardless of the closure or opening of t 1 said register contacts.

at. In telephone system, the combination with a telephone line, of acentral oiiice connection switch, a line meter having a. circuit adaptedto completed by said connection switch, the aid line meter havingcontacts adapted to be closed when the said line meter is energized, anoperating winding for the said line meter, a second winding therefor,and adapted to be placed in multiple with the said its; winding when thesaid contacts are closed, a marginal relay and a source oi registrationcurrent adapted to be connected to the said line meter when a connectingcircuiit is associated with the said telephone line, by the operation ofthe said connection si itch, an armature tor the said marginal reladapted to be operatel when the said line meter contacts are closed, butnot operated prior to the closure of the said con tacts, means under thecontrol of the said armature to cause the said registratioi'i source ofcurrent 3e disassociated from to said line m "er when the said armatureis operated, it. a relatively low resistance non-inductive shunt for tle operating winding of the sad marginal relay.

In an electfcal metering ystem, the combination with anelectromugnetically operated nie'er having an energizing winding, anener izing circuit including a source oi current for the said winding, amarginal the said ci 'cuit, means to apply relay 101 the said source or"current to the said circuit to operate the said n cter. a contactcontroller by the said meter and adapted when the meter is rullyoperated to alter the flow of current in the said energizing circuit tooperate the saicr marginal relay. a contact in the said energizingcircuit un l r the control of the said marginal relay adapted to openthe said energizing circuit when the said marginal rela is operated, anda holding 'd marginal relay adapted operated after an initial tomaintain 1 operation.

6. In an electrical metering system, the combination with anelectromagnetically operated meter having an energizing winding, anenergizing circuit including a source of current for the said winding. amarginal relay for the said circuit, means to apply the said source ofcurrent to the said circuit to ope trolled by the s the meter is ieterand adapted when ully operated to alter the {low of current in the saidenergizing circuit to marginal relay, a contact in operate the said thesaid energizing circuit under the control of the said marginal relayadapted to open the said energizing circuit when the said marginal relayis operated. a holding circuit for the said marginal relay adapted tomaintain it operated after an initial operation, and two windings forthe said mar ginal relay, the first winding connected in the saidenergizing circuit and the second winding in the said holding circuit.

7. In an electrical metering system, the combination with anelectromagnetically eperat d meter having an energizing winding, anenergizing circuit including a source of current for the said winding, amarginal relay for the said circuit, means to apply the said source oicurrent to the said circuit to operate the said meter, a contactcontrolled hy the said meter and adapted when the meter is fullyoperated to alter the flow of current in the said energizing circuit toopera e the said marginal relay, a contact in the said energizingcircuit under the control (it the said marginal relay adapted to openthe said energizing circuit when the said marginal relay is operated, aholding circuit for the said marginal relay adapted to maintain itoperated after an initial operation, two windings tor the said marginalrelay, the first winding connected in the said energizing circuit andthe second winding in the said holding circuit, and a relatively lowresistance non-inductive resistance unit connected across the terminalsof the said first named winding.

In a telephone system, the combination ith a calling telephone line, ofa called telephone line, substations -t'or the said lines, a lineinterconnecting circuit for interconnecting the said lines terminatingat each end in connection terminals adapted to be associated withcooperating connection terminals tor the lines when connection is madetherewith, a relay associated with each of the said connectionterminals, each adapted to be placed under the control of the substationapparatus of the associated line, a call register associated with thecalling line and having its energizing circuit carried through one ofthe said connection terminals, a relay associated with the said lineinterconnecting circuit having a plurality of armatures, contactsseparately controlled by each of the said armatures, one of the saidarmat-ures being a fast operating armature and the other armature beinga relatively slow operating armature, means to energize the said relayunder the joint control of both of the said substation controlledrelays, means to condition the line interconnecting circuits tor anoperation of the said calling line register, the said means includingthe said contacts operated by the fast operating armature, and means toagply the said source of current to the said register circuit by thecontacts operated by the said slow operating armature.

9. In a telephone system, the combination with a telephone line, of acentral oifice connect-ion switch having connection terminals connectedwith the talking strands of the said telephone line, aline meter for thesaid line connected to one of the said talking strands, the said linemeter having contacts adapted to be closed when the said line meter isenergized, a marginal relay and a source of registration current adaptedto be connected to the said line meter through the said line connectionswitch terminals when a line interconnecting circuit is associated withthe said telephone line, by the operation of the said connection switch,an armature for the said marginal relay adapted to be operated when thesaid line meter contacts are operated, but not to be operated prior tothe closure oft the said contacts, and means under the control of thesaid arm ature to cause the said registration source oi current to bedissociated from the said line meter when the said armature is operated.

10. In a telephone system, the combination with a telephone line, of acentral otlice connection switch having connection terminals connectedwith the talking strands of the said telephone line, a line meter forthe said line connected to one of the said talking strands, the saidline meter having contacts adapted to be closed when the said line meteris energized, a marginal relay and a source of registration currentadapted to he connected to the said line meter through the said lineconnection switch terminals when a line interconnecting circuit isassociated with the said telephone line, by the operation of the saidconnection switch, an armature for the said marginal relay adapted to beoperated when the said line meter con tacts are operated, but not to beoperated prior to the closure of the said contacts,

means under the control of the said armature to cause the saidregistration source of current to be dissociated from the said linemeter when the said. armature is operated, and a holding circuit for thesaid marginal relay including a normally short circuited windingthereof.

11. In a telephone system, the combination with a telephone line, of acentral oiiice connection switch having connection terminals connectedwith the talking strands oi the said telephone line, a line meter forthe said line connected. to one of the talking strands, the sand linemeter having contacts adapted to be closed when the said line meter ison ergized, a marginal relay and a source of registration currentadapted to be connected to the said line meter through the said lineconnection switch terminals when a line in terconnecting circuit isassociated with the said telephone line, by the operation of the saidconnection switch, an armature for the said marginal relay adapted to beoperated when the said line meter contacts are operated, but not to beoperated prior to the closure of the said contacts, means under thecontrol of the said armature to cause the said registration source ofcurrent to be dissociated from the said line meter when the saidarmature is operated, and a holding circuit for the said marginal relayunder the control of contacts of the said marginal relay and the saidconnection switch.

12. In a telephone system, the combination with a telephone line, of acentral otfice connection switch having connection terminals connectedwith the talking strands of the said telephone line, a line meter forthe said line connected to one of the said talking strands, the saidline meter having contacts adapted to be closed when the said line meteris energized, a marginal relay and a source of registration currentadapted to be connected to the said line meter through the said lineconnection switch terminals when a line interconnecting circuit isassociated with the said telephone line, by the operation of the saidconnection switch, an armature for the said marginal relay adapted to beoperated when the said line meter contacts are operated, but not to beoperated prior to the closure of the said contacts, means under thecontrol of the said armature to cause the said registration source ofcurrent to be dissociated tromthe said line meter when the said armatureis operated, and a holding circuit for the said marginal relay includinga normally short circuited winding thereof, the other circuit for thesaid winding including normal contacts for the said marginal relay.

13. In a telephone system, the combination with a telephone line, of acentral otfice connection switch having connection terminals connectedwith the talking strands of the said telephone line, a line meter forthe said line cgnnected to one of the said talking strands, the saidline meter having contacts adapted to be closed when the said line meteris energized, a marginal relay and a source of registration currentadapted to be connected to the said line meter through the said lineconnection switch terminals when a line interconnecting circuit isassociated with the said telephone line, by the operation of the saidconnection switch, an armature oi the said marginal relay adapted to beoperated when the said line meter contacts are operated, but not to beoperated prior to the closure of the said contacts, and means un der thecontrol of the said armature to cause the said registration source ofcurrent to be dissociated from the said line meter when the saidarmature is operated, said means including normally open contacts forthe said marginal relay.

14. In a telephone system, the combination with a telephone line, of acentral oiiice connection switch having connection terminals connectedwith the talking strands of the said telephone line, a line meter forthe said line connected to one of the said talking strands, the saidline meter having contacts adapted to be closed when the said line meteris energized, a marginal relay and a source of registration currentadapted to be connected to the said line meter through the said lineconnection switch terminals when a line interconnecting circuit isassociated with the said telephone line, by the operation of the saidconnection switch, an armature for the said marginal relay adapted to beoperated when the said line meter contacts are operated, but not to beoperated prior to the closure of the said contacts, means under thecontrol of the said armature to cause the said registration source ofcurrent to be dissociated from the said line meter when the saidarmature is operated, an operating winding for the said line meter inthe said circuit completed by said connection switch, a second windingtherefor and adapted to shunt the said first winding when the saidregister contacts are operated, the windings of the said register beingrelatively so proportioned that the magnetic energization of the saidregister is independent of the closure or opening of said registercontacts.

15. In a telephone system, the combina tion of a telephone line, of acentral ofiice connection switch having connection terminals connectedwith the talking strands of the said telephone line, a line meter forthe said line connected to one of the said talking strands, the saidline meter having contacts adapted to be closed when the said line meteris energized, a marginal relay and a source of registration currentadapted to be connected to the said line meter through the said lineconnection switch terminals when a line interconnecting circuit isassociated with the said telephone line, by the operation of the saidconnection switch, an armature for the said marginal relay adapted to beoperated when the said line meter contacts are operated, but not to beoperated prior to the closure of the said contacts, means under thecontrol of the said armature to cause the said registration source ofcurrent to be dissociated from the said line meter when the saidarmature is operated, and a relatively low resistance non-inductiveshunt for the operating winding of the said marginal relay.

16. In a telephone system, the combination with a calling telephoneline, a calling substation receiver for the said line, a connectionswitch adapted to be associated therewith, including calling and calledterminals, a repeating coil inductively linking the said terminals,means to cause an electric change of potential in the said connectioncircuit, and means including a short circuit of one of the windings ofsaid repeating coil to prevent the said electric changed potentialviolently operating the diaphragm of the calling substation telephonereceiver.

In witness whereof, I hereunto subscribe my name this 19th day ofSeptember, A. D.

FRANK M. SLOUGH.

